1. Field of the Invention
The present invention relates to a device having a part actuated via a drive apparatus, preferably a handling device having an actuated positioning part or a press having a press ram actuated by the drive apparatus.
2. Related Prior Art
Devices of this kind are commonly known from the prior art; they serve as presses, for example on the one hand for shaping objects and on the other hand for fitting together workpieces that must be assembled under pressure. The handling devices used in particular in the press sector are used, for example, to position under the press the workpieces that are to be fitted together.
On the one hand fluid-actuated piston-cylinder units, and on the other hand spindle drives that are actuated via an electric motor, are known as the drive apparatus for devices of this kind.
Especially in the case of presses that must perform a very high number of press strokes during their service life, it is inherently necessary to lubricate the moving parts. In the case of spindle drives, for example, it is known that if they are not continuously lubricated during operation, they fail due to insufficient lubrication after approximately 500,000 strokes.
In spindle drives of this kind which have either a driven, axially nondisplaceable threaded spindle or a driven, axially nondisplaceable spindle nut, lubrication of the threads between the threaded spindle and spindle nut is, however, of very complex configuration, especially in presses, since this region in the interior of the press is poorly accessible. For this reason, it is impossible to use such spindle drives in so-called electric presses if such electric presses are to be operated in continuous service.